In some systems, a group management system facilitates secure communications between multiple user nodes in a distributed communication environment. Communications among members of a defined group can be enabled using distributed end user devices operating in the networked user nodes, where multiple user nodes each include an intermediate communication device that establishes a communication channel with another intermediate communication device in another user node. The intermediate communication devices (e.g., cellphones, smartphones, laptop computers, tablets and others) are linked to a communication network and the group management system, which implements communications between user devices (via a communication application in each intermediate communication device) in the defined group of user nodes.
The group management system processes communication messages transmitted by a group member user node to determine its identity, thereafter identifying one or more active communication groups with which the first user node is affiliated. In connection with at least one of the identified active communication groups, the group management system relays the group member user node's transmitted communication messages to active recipient nodes affiliated with the group. Various groups may use such systems for real-time communication among the various groups' members. In some cases it may be desirable to deliver supplemental audio to some or all group members as part of the group's active communications.